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1983 Chevy Malibu V8. Buck, Lurch and How!

No, not a law firm, this is how the car behaves especialy at 45 and above, usualy when accelerating.

Idles and cruzes at low speed 25MPH no problem, but hit the gas to get moving quick and sometimes it just seems to lose all power and then lurch and buck. Sometimes drives well at 55-60 and just starts to get dumpy, loses power - but never stals out - and I end up w/ my hazards on doing 35 in the slow lane, intermitenly lurching jerking all the way home. Fuel pump? Carburator? Transmission?

Car talk Rocks! Any help is much appreciated.

A few things to check:

Fuel pump pressure

Dirty fuel/air filter

Slight possibility of moisture or foreign matter (dirt) in fuel tank being sucked up into the fuel take-up pipe.
Do you know if the sock is still on the pick-up pipe?

Improper fuel/air mix

Possible pin-hole leak in fuel line sucking in air. Any raw fuel smell?

Old spark plugs and/or plug wires?

You don’t mention any service being done. Has there?

Thank you for such prompt resonse! Bought it about a year ago. repaced stearing box, not much else of consequence (tires, some shot out wires & hoses). its genrealy in great shape. I’m about to try dry gas treatment as it did sit a bit this winter. A friend suggested the fuel pump went bad but that dosnt explain it still working somewhat does it? it also smokes from the engine block once it gets warm but old engines = leaks so im not sure if its related.

Others may disagree but I don’t put much faith in all those additives for this and that.

I don’t remember these fuel pumps getting weak before quitting.

Was the fuel filter replaced?

On the issue of possible moisture, I’d remove the tank, the old gas and dry the tank right out and check for dirt and rust.

Make certain the tank is solid. If there is a rusted area (Maybe on top where water could sit) check it with a screwdriver.

The metal may be rusted enough to create a pinhole air leak, which in turn would allow water to enter.

This fuel pump is block mounted correct?

On '80s V8’s, a pushrod is used between the camshaft and the pump rocker.
A quick test to check for even fuel flow is to disconnect the primary wire from the coil to the distributor to prevent the engine from starting while cranking the starter.

Disconnect the fuel line at the carb and aim it into a suitable container and
and while a helper cranks the engine over, watch that there is well defined spurts of fuel being ejected.

(I would try this when the engine is WARM, (not hot so you don’t burn yourself) and at the same time, the fuel pump is warmed up.

If it doesn’t pump steady spurts you’ll know you’ll have to replace the pump. (There MAY be the slight possibility the pushrod is worn)

(Make certain to scrape all the old gasket off and apply a sealer to the bolt threads)
Be careful tightening the pump bolts back on. Tighten both snug then 1/4 turn should do it.

Replace the primary wire to the coil and distributor. Check for a leak while the engine is running and after the block and pump has cooled off too.
Check the bolts after a few runs.

One other thing is the ignition system may have a fault. Maybe.

It’s been a lonnnngggg time since I worked on these so I’m hoping I gave you the right info.

I imagine I’ll be set straight if wrong. (Atleast I hope so)

Oil leaks may be from the valve covers and MAY be running down onto the exhaust or the fan may be blowing it back.

Oil leaks won’t get fixed on their own, only get worse.

Me? I hate the oil leak mess on the driveway.
It gets on the dog’s paws and if it doesn’t get sick and die form licking the paws, the oil gets spread through the house.
Even if you wipe their paws.